I just setup a headless server. I would like to administrate this via serial, but I won't always have a serial connection plugged in. If I configure GRUB_TERMINAL="console serial", grub2 will not automatically boot when my serial connection is not plugged in. Is there any way to have serial configured as a backup in grub2 so that I can control grub2 if there is a serial connection, but so that the machine still boots otherwise?